Saliva testing as noninvasive way for monitoring exercise-dependent response in teenage elite water polo players: A cohort study

Excessively increased training volume and/or intensity and competition can lead to development of overtraining syndrome, causing a performance decrement in athletes. Tracking individual response to exercise intensity is crucial for establishing recovery strategies.We assessed the exercise intensity-dependent variability of stress response biomarkers, namely cortisol (C), testosterone (T), s-IgA, and advanced oxidation protein products (AOPP), in saliva samples of teenage elite water polo players. Saliva was collected on a day of training match (T1) and a day of competitive match (T2), at morning, before and after match.Cortisol/proteins and testosterone/proteins concentrations decreased throughout day T1, whereas increased throughout day T2. The highest values were measured after match on day T2 (2.5 ± 0.5 vs 14.6 ± 6.3 ng/mg; 0.061 ± 0.024 vs 0.371 ± 0.15 ng/mg, respectively). sIgA/proteins and AOPP/proteins concentrations increased throughout both days, and were higher after T2 match than T1 one (respectively, 1073.0 ± 438.2 vs 71.0 ± 17.3 μg/mg; 78.05 ± 24.2 vs 15.98 ± 3.16 nmol/mg, P = .003). Significant differences between concentrations of different biomarkers recorded on T1 and T2 were found only for AOPP, suggesting an increased oxidative stress on day T2. Free testosterone/cortisol ratio on day T2 was lower than that at morning (0.053 ± 0.021 vs 0.107 ± 0.031), indicating an increased catabolic response after competitive match.A highly significant positive correlation was found between Cortisol/Proteins and Testosterone as well as s-IgA/Proteins on day T1, and between Cortisol/Proteins and AOPP on day T2.In conclusion, we found that different types of activities, such a training or competitive session can affect the hormonal response, immunity, and oxidative stress, thereby modulating athletic performance.Our findings also confirm the usefulness of saliva testing as noninvasive way for monitoring the individual response to changes in exercise intensity in teenage elite water polo players.

Influence of the SOD2 A16V gene polymorphism on alterations of redox markers and erythrocyte membrane fatty acid profiles in patients with multiple chemical sensitivity

Chronically increased oxidative stress has been reported in patients with multiple chemical sensitivity (MCS). Recently, a single nucleotide polymorphism of the gene coding for mitochondrial superoxide dismutase (SOD2), namely the missense substitution A16V (C47>T) resulting in alteration of SOD2 enzyme activity, has been reported to be associated with MCS. However, the influence of SOD2 A16V genetic background on redox status of patients with MCS has not yet been investigated. Here, the results of a retrospective analysis aimed to evaluate the role of the SOD2 A16V polymorphism in the alterations of antioxidant defense markers as well as fatty acid (FA) composition of erythrocyte membranes in 67 patients with MCS matched with 55 healthy controls is reported. The mutated SOD2 V16 variant was observed more frequently in the MCS group compared with the control group, and this difference was statistically significant. The most common genotype in both groups was the heterozygous SOD2 AV16 variant, whereas the mutated SOD2 VV16 variant was more frequently observed in the MCS group, although the difference was not significant. The MCS cohort showed significantly depleted levels of plasma total antioxidant activity, ubiquinol, erythrocyte reduced glutathione and membrane polyunsaturated FA levels, coupled with significant increases in glutathione peroxidase activity, likely accounting for sustained detoxification from lipoperoxides. Notably, the highest levels of oxidative stress were found in patients with MCS bearing the genotype SOD2 AA16, whereas intermediate levels were found in patients bearing the heterozygous AV16 genotype. Healthy subjects bearing the SOD2 AA16 genotype also showed increased oxidative stress compared with carriers of other SOD2 genotypes. Despite the need for further confirmations in larger cohorts, due to MCS population genetic heterogeneity, these preliminary findings suggest that SOD2 defective activity makes certain patients with MCS more susceptible to developing oxidative stress following a chronic daily exposure to pro-oxidant insults.

Changes in the Biomarkers of Oxidative/Nitrosative Stress and Endothelial Dysfunction Are Associated with Cardiovascular Risk in Periodontitis Patients

Patients with cardiovascular disease (CVD) and periodontitis (PT) show shared risk factors as result of the altered molecular mechanisms associated with pathological conditions. The aim of our study was to evaluate if the plasma biomarkers associated with endothelial dysfunction may also be related to alterations in the inflammatory status in peripheral blood mononuclear cells (PBMC). Patients with PT, coronary heart disease (CHD), or both diseases as well as controls were enrolled. Plasma levels of coenzyme Q10 (CoQ10), 3-nitrotyrosine (NT), and asymmetric dimethylarginine (ADMA) were assessed using HPLC. mRNA levels of caspase-1 (CASP1), NLR family pyrin domain containing 3 (NLRP3), and tumor necrosis factor-α (TNF-α) in PBMC from the recruited subjects were quantified using real-time PCR. Patients with PT + CHD showed lower CoQ10 plasma levels and increased concentrations of NT in comparison to healthy subjects. ADMA levels were higher in CHD and PT + CHD patients compared to controls. Transcript levels of CASP1, NLRP3, and TNF-α were up-regulated in PBMC from all patient groups when compared to healthy subjects. Our results suggest a possible causal link between oxidative stress, high levels of NT and ADMA, and inflammasome activation, which may be involved in the endothelial inflammatory dysfunction leading to the pathogenesis and progression of CHD in PT patients.

A Flavonoid-Rich Extract from Bergamot Juice, Alone or in Association with Curcumin and Resveratrol, Shows Protective Effects in a Murine Model of Cadmium-Induced Testicular Injury

It is known that cadmium damages testis structure and functionality. We examined the effects of nutraceuticals such as a flavonoid-rich extract of bergamot juice (BJe), alone or in association with curcumin (Cur) and resveratrol (Re), on mice testicular dysfunction caused by cadmium chloride (CdCl₂). Controversial data on the protective effects of Cur and Re are available, while no evidence on the possible role of BJe exists. Adult male C57 BL/6J mice were administered with CdCl₂ and treated with Cur, Re, or BJe alone or in combination for 14 days. Then, testes were removed and processed for molecular, structural, and immunohistochemical analyses. CdCl₂ increased the mRNA of IL-1β, TNF-α, p53, and BAX while reduced that of Bcl-2 and induced tubular lesions and apoptosis of germinal cells. Cur, Re, and BJe at 40 mg/kg significantly improved all of these parameters and events, although BJe at 20 mg/kg showed a lower protective effect. The association of Cur, Re, and BJe at both doses of 50/20/20 and 100/20/40 mg/kg brought each parameter close to those of the control. Our results indicate that the nutraceuticals employed in this study and their associations exert a positive action against Cd-induced testicular injury, suggesting a possible protection of testis functionality in subjects exposed to environmental toxicants.

Baicalin-Induced Autophagy Preserved LPS-Stimulated Intestinal Cells from Inflammation and Alterations of Paracellular Permeability

Several studies have demonstrated a relevant role of intestinal epithelial cells in the immune response and in chronic inflammatory conditions, including ulcers, colitis, and Crohn's disease. Baicalin (BA), extracted from the root of Scutellaria baicalensis, has various beneficial healthy effects, including anti-inflammatory activity. However, few studies have evaluated BA effects on autophagic signaling in epithelial cell response to inflammatory stimuli. To explore possible beneficial effects of BA, HT-29 cells were exposed to lipopolysaccharide (LPS), in presence or absence of BA, for 4 h. We evaluated mRNA levels of autophagy-related genes and cytokines, triggering inflammatory response. Furthermore, the expression of claudin 1, involved in the regulation of paracellular permeability was analyzed. BA treatment repressed LPS-induced expression of TNF-α and IL-1β. The down-regulation of autophagy-related genes induced by LPS was counteracted by cell pretreatment with BA. Under these conditions, BA reduced the NF-κB activation caused by LPS. Also, BA restored mRNA and protein levels of claudin 1, which were reduced by LPS. In conclusion, in intestinal epithelial cells BA regulates the NF-κB activation and modulates both autophagic and inflammatory processes, leading to an improvement of paracellular permeability. These results suggest that the anti-inflammatory effects of BA can be associated to the regulation of autophagic flux.

CO2 Pneumoperitoneum Effects on Molecular Markers of Tumor Invasiveness in SH-SY5Y Neuroblastoma Cells

INTRODUCTION

 CO₂ pneumoperitoneum can influence the biological behavior of neuroblastoma (NB). Angiogenesis and genetic features are responsible for malignant phenotype of this tumor. We examined the CO₂ effects on N-Myc, vascular endothelial growth factor (VEGF), and matrix metalloproteinase-2 (MMP-2) expression as critical biomarkers of tumor invasiveness, in NB cells without N-Myc amplification.

MATERIALS AND METHODS

 SH-SY5Y cells were exposed to CO₂ (100%) at 15 mm Hg pressure for 4 hours and then moved to normal condition for 24 hours. Control cells were incubated with 5% CO₂ for the same time. In control and CO₂-exposed cells, the messenger ribonucleic acid (mRNA) levels of hypoxia-inducible factor (HIF)-1α, HIF-2α, VEGF-A, and MMP-2 were quantified by real-time polymerase chain reaction. N-Myc expression was evaluated by Western blot analysis.

RESULTS

 The exposure to 15 mm Hg CO₂ (100%) for 4 hours induced an increase in HIF-1α, but not in HIF-2α, mRNA levels. No differences were observed in N-Myc expression between exposed and control cells at each incubation time. Similarly, no significant differences were found for VEGF-A and MMP-2 transcript levels. In CO₂ exposed cells, we observed only a slight increase in both VEGF-A and MMP-2 mRNA levels after 4 and 24 hours in comparison to controls.

CONCLUSION

 In our study, the hypoxic environment induced by CO₂ exposure does not affect the expression of critical biomarkers of NB aggressiveness, such as N-Myc, VEGF, and MMP-2, in human SH-SY5Y NB cells without N-Myc amplification. These data suggest that CO₂ pneumoperitoneum might not adversely impact NB cell invasiveness; however, it is necessary to evaluate these effects in others in vitro and in vivo models.

Is Melatonin the Cornucopia of the 21st Century?

Melatonin, an indoleamine hormone produced and secreted at night by pinealocytes and extra-pineal cells, plays an important role in timing circadian rhythms (24-h internal clock) and regulating the sleep/wake cycle in humans. However, in recent years melatonin has gained much attention mainly because of its demonstrated powerful lipophilic antioxidant and free radical scavenging action. Melatonin has been proven to be twice as active as vitamin E, believed to be the most effective lipophilic antioxidant. Melatonin-induced signal transduction through melatonin receptors promotes the expression of antioxidant enzymes as well as inflammation-related genes. Melatonin also exerts an immunomodulatory action through the stimulation of high-affinity receptors expressed in immunocompetent cells. Here, we reviewed the efficacy, safety and side effects of melatonin supplementation in treating oxidative stress- and/or inflammation-related disorders, such as obesity, cardiovascular diseases, immune disorders, infectious diseases, cancer, neurodegenerative diseases, as well as osteoporosis and infertility.

Vitamin D Status Modulates Inflammatory Response in HIV+ Subjects: Evidence for Involvement of Autophagy and TG2 Expression in PBMC

Conflicting results on the involvement of vitamin D deficiency in inflammatory and immune response in HIV+ subjects are reported. We aimed to characterize the possible influence of vitamin D status on changes in expression of tissue transglutaminase gene (TGM2) and other genes involved in inflammatory response and autophagy in peripheral blood mononuclear cells (PBMC) from HIV+ subjects. HIV+ subjects (n = 57) under antiretroviral therapy (ART) and healthy controls (n = 40) were enrolled. mRNA levels of 1-alpha-hydroxylase (CYP27B1), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), TGM2, microtubule-associated protein 1A/1B-light chain 3 (LC3), autophagy-related 5 homolog (ATG5), and Beclin 1 (BECN1) were quantified by real-time PCR. In HIV+ subjects, 25(OH)D₃ plasma levels were negatively correlated with time since HIV diagnosis. In PBMC from HIV+ subjects, increases in gene expression of TNF-α and IFN-γ in comparison to controls were observed. The highest increase in TNF-α transcripts was observed in HIV+ subjects with deficient 25(OH)D₃ levels. Autophagy-related genes LC3, ATG5, and BECN1 were down-regulated in HIV+ subjects. Moreover, TGM2 transcripts were up-regulated in PBMC from HIV+ subjects with 25(OH)D3 deficiency. Changes observed in PBMC from HIV+ subjects appeared to be dependent on vitamin D status. The present results suggest that vitamin D deficiency is associated with changes in the expression of markers of inflammation and autophagy, resulting in immune cell dysfunction.

Neuroprotective Effect of Bergamot Juice in 6-OHDA-Induced SH-SY5Y Cell Death, an In Vitro Model of Parkinson's Disease

Much evidence suggests that both oxidative stress and apoptosis play a key role in the pathogenesis of Parkinson’s disease (PD). The present study aims to evaluate the protective effect of bergamot juice (BJ) against 6-hydroxydopamine (6-OHDA)- or H₂O₂-induced cell death. Treatment of differentiated SH-SY5Y human neuroblastoma cells with 6-OHDA or H₂O₂ resulted in cell death that was significantly reduced by the pre-treatment with BJ. The protective effects of BJ seem to correlate with the reduction of intracellular reactive oxygen species and nitric oxide generation caused by 6-OHDA or H₂O₂. BJ also attenuated mitochondrial dysfunction, caspase-3 activation, imbalance of pro- and anti-apoptotic proteins, MAPKs activation and reduced NF-ĸB nuclear translocation evoked by neurotoxic agents. Additionally, BJ exhibited excellent antioxidant capability in cell-free assays. Collectively, our results suggest that BJ exerts neuroprotective effect through the interplay with specific cell targets and its antioxidant activity, making it worthy of consideration for the management of neurodegenerative diseases.

The SNP rs2298383 Reduces ADORA2A Gene Transcription and Positively Associates with Cytokine Production by Peripheral Blood Mononuclear Cells in Patients with Multiple Chemical Sensitivity

Systemic inflammation and immune activation are striking features of multiple chemical sensitivity (MCS). The rs2298383 SNP of ADORA2A gene, coding for adenosine receptor type 2A (A2AR), has been involved in aberrant immune activation. Here we aimed to assess the prevalence of this SNP in 279 MCS patients and 238 healthy subjects, and its influence on ADORA2A, IFNG and IL4 transcript amounts in peripheral blood mononuclear cells of randomly selected patients (n = 70) and controls (n = 66) having different ADORA2A genotypes. The ADORA2A rs2298383 TT mutated genotype, significantly more frequent in MCS patients than in controls, was associated with a three-fold increased risk for MCS (O.R. = 2.86; C.I. 95% 1.99–4.12, p < 0.0001), while the CT genotype, highly prevalent among controls, resulted to be protective (O.R. = 0.33; C.I. 95% 0.224–0.475, p < 0.0001). Notably, ADORA2A mRNA levels were significantly lower, while IFNG, but not IL4, mRNA levels were significantly higher in TT MCS patients compared with controls. A significant negative correlation was found between ADORA2A and both IFNG and IL4, while a significant positive correlation was found between IFNG and IL4. These findings suggest that A2AR defective signaling may play a relevant role in PBMC shift towards a pro-inflammatory phenotype in MCS patients.

Hypoxia-Dependent Expression of TG2 Isoforms in Neuroblastoma Cells as Consequence of Different MYCN Amplification Status

Transglutaminase 2 (TG2) is a multifunctional enzyme and two isoforms, TG2-L and TG2-S, exerting opposite effects in the regulation of cell death and survival, have been revealed in cancer tissues. Notably, in cancer cells a hypoxic environment may stimulate tumor growth, invasion and metastasis. Here we aimed to characterize the role of TG2 isoforms in neuroblastoma cell fate under hypoxic conditions. The mRNA levels of TG2 isoforms, hypoxia-inducible factor (HIF)-1α, p16, cyclin D1 and B1, as well as markers of cell proliferation/death, DNA damage, and cell cycle were examined in SH-SY5Y (non-MYCN-amplified) and IMR-32 (MYCN-amplified) neuroblastoma cells in hypoxia/reoxygenation conditions. The exposure to hypoxia induced the up-regulation of HIF-1α in both cell lines. Hypoxic conditions caused the up-regulation of TG2-S and the reduction of cell viability/proliferation associated with DNA damage in SH-SY5Y cells, while in IMR-32 did not produce DNA damage, and increased the levels of both TG2 isoforms and proliferation markers. Different cell response to hypoxia can be mediated by TG2 isoforms in function of MYCN amplification status. A better understanding of the role of TG2 isoforms in neuroblastoma may open new venues in a diagnostic and therapeutic perspective.

The link between the AMPK/SIRT1 axis and a flavonoid-rich extract of Citrus bergamia juice: A cell-free, in silico, and in vitro study

A previous report indicated that the flavonoid-rich extract of bergamot juice (BJe) exerts an anti-inflammatory effect through the activation of SIRT1 in leukemic monocytes THP-1 exposed to lipopolysaccharide (LPS). In this study, we deeply investigate the mode of action of BJe, along with its major flavonoids on SIRT1 through cell-free, in silico, and in vitro experimental models. In the cell-free assay, all the tested compounds as well as the whole BJe inhibited the deacetylase activity of SIRT1. This finding was reinforced by the results of the in silico study. In THP-1 cells exposed to LPS, a reduction of SIRT1 activity was observed, effect that was reverted by the pre-incubation with either BJe or its major flavonoids. This effect was also observed at gene level. Employing an activator and an inhibitor of AMP-activated protein kinase (AMPK; AICAR and dorsomorphin, respectively), we discovered its involvement in the activation of SIRT1 elicited by BJe or its major flavonoids in whole cell. Our study indicates the dual role of BJe and its components, depending on the employed experimental model as well as reveals their mode of action on the AMPK/SIRT1 axis, suggesting their role as promising candidates in pathologies in which this axis is implied.

A flavonoid-rich extract from bergamot juice prevents carcinogenesis in a genetic model of colorectal cancer, the Pirc rat (F344/NTac-Apcam1137)

PURPOSE

To determine the potential of a flavonoid-rich extract from bergamot juice (BJe) to prevent colorectal carcinogenesis (CRC) in vivo.

MAIN METHODS

Pirc rats (F344/NTac-Apc^am1137), mutated in Apc, the key gene in CRC, were treated with two different doses of BJe (35 mg/kg or 70 mg/kg body weight, respectively) mixed in the diet for 12 weeks. Then, the entire intestine was surgically removed and dissected for histological, immunohistochemical and molecular analyses.

RESULTS

Rats treated with BJe showed a significant dose-related reduction in the colon preneoplastic lesions mucin-depleted foci (MDF). Colon and small intestinal tumours were also significantly reduced in rats supplemented with 70 mg/kg of BJe. To elucidate the involved mechanisms, markers of inflammation and apoptosis were determined. Compared to controls, colon tumours from BJe 70 mg/kg-supplemented rats showed a significant down-regulation of inflammation-related genes (COX-2, iNOS, IL-1β, IL-6 and IL-10 and Arginase 1). Moreover, in colon tumours from rats fed with 70 mg/kg BJe, apoptosis was significantly higher than in controls. Up-regulation of p53 and down-regulation of survivin and p21 genes was also observed.

CONCLUSIONS

These data indicate a strong chemopreventive activity of BJe that, at least in part, is due to its pro-apoptotic and anti-inflammatory actions. This effect could be exploited as a strategy to prevent CRC in high-risk patients.

Ex vivo evaluation of the effects of a white grape juice extract on lymphocytic mitochondrial functions

The physio-pathological role of mitochondria in aging and age-related diseases has stimulated the search for compounds able to promote mitochondrial functionality. Our study was designed to evaluate the effect of a white grape juice extract (WGJe) on mitochondrial activity, in an ex vivo experimental model consisting of activated lymphocytes obtained from a younger age group and an older age group of subjects. WGJe steadily decreased the lymphocytic mitochondrial mass in the older subjects, without a relevant effect in their younger counterpart, and significantly enhanced Δψm in both groups investigated. Finally, WGJe reduced the endogenous mitochondrial production of H₂O₂ in all subjects. The results support the potential use of WGJe to improve mitochondrial functionality, thus maintaining human health and slowing down aging.

Anti-Inflammatory and Tissue Regenerative Effects of Topical Treatment with Ozonated Olive Oil/Vitamin E Acetate in Balanitis Xerotica Obliterans

Balanitis xerotica obliterans (BXO) is a chronic inflammatory skin disorder, considered the male genital variant of lichen sclerosus. Anti-inflammatory drugs are commonly used in BXO. We evaluated the effects of an innovative formulation of ozonated olive oil with vitamin E acetate (OZOILE®) on the inflammatory status and tissue remodeling in male children with BXO. The mRNA transcripts of proteins involved either in inflammation or in dynamics of tissue regeneration were analyzed by quantitative real-time PCR, in foreskins affected by BXO removed from patients untreated or treated with OZOILE® cream for 7 days before circumcision. We found a significant reduction in mRNA levels of IL-1β, TNF-α, INF-γ, transglutaminase 2 and NOS2 in foreskins treated with OZOILE® in comparison to untreated ones (p < 0.001). No significant differences were observed in NF-κB activation in the specimens obtained from treated and untreated patients. Hence, OZOILE® treatment up-regulated hypoxia-inducible factor (HIF)-1alpha, vascular endothelial growth factor (VEGF) and E-cadherin gene expression (p < 0.001). The treatment with OZOILE® showed effective results in children affected by BXO by reducing the inflammatory process and stimulating mechanisms for tissue regeneration of the foreskin. A randomized clinical trial on a large number of children affected by BXO might be useful to verify the efficacy of topical treatment with OZOILE®.

Anticancer Potential of Citrus Juices and Their Extracts: A Systematic Review of Both Preclinical and Clinical Studies

Background: During the last decades, a huge body of evidence has been accumulated suggesting that Citrus fruits and their juices might have a role in preventing many diseases including cancer.

Objective: To summarize the numerous evidences on the potential of Citrus juices and their extracts as anticancer agents.

Data sources: A systematic review of articles written in English using MEDLINE (1946-present), EMBASE (1974-present) and Web of Sciences (1970-present) was performed independently by two reviewers. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, cancer, neoplasm, neoplasia, tumor, metastasis, carcinogenesis, proliferation. The last search was performed on March 16th, 2017.

Study selection: Study selection and systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Prior to the beginning of the review, Authors defined a checklist for inclusion criteria, thus including articles which meet the following: (i) published on peer-reviewed scientific journals; (ii) Citrus juice used alone; (iii) extracts derived from Citrus juice; (iii) for preclinical studies, an exposure time to Citrus juices and their extracts more than 24 h. Reviews, meta-analyses, conference abstracts and book chapters were excluded.

Data extraction: Three reviewers independently performed the extraction of articles.

Data synthesis: 22 papers met our inclusion criteria and were eligible for inclusion in the final review. According to the kind of study, the selected ones were further divided in preclinical (n = 20) and observational (n = 2) studies.

Conclusion: The studies discussed in this review strongly corroborate the role of Citrus juices and their derivatives as potential resource against cancer.

Influence of MTHFR Genetic Background on p16 and MGMT Methylation in Oral Squamous Cell Cancer

Genetic polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) enzyme may influence DNA methylation. Alterations in DNA methylation patterns of genes involved in the regulation of the cell cycle, DNA repair, cell adherence and metastasis process are known to contribute to cancer development. In this study, the influence of the MTHFR C677T and A1298C gene polymorphisms on global DNA methylation and site-specific methylation on p16 and O⁶-methylguanine-DNA methyltransferase (MGMT) gene promoters was investigated in patients with oral squamous cell cancer (OSCC). To this aim, methylation studies were carried out by using genomic DNA isolated from saliva samples of 58 OSCC patients and 90 healthy controls. The frequency of the CT/AC and TT/AA genotypes was significantly higher in patients than in controls. Whereas no difference in global DNA methylation levels was observed between patients and controls, a higher frequency of methylation at both p16 and MGMT gene promoters was detected in patients compared with controls. A significant association between MTHFR gene polymorphisms and p16 and MGMT gene promoter methylation was found. The frequency of p16 and MGMT methylation was around 60% in patients with either the CT/AC or TT/AA genotype. Our results suggest that hypermethylation of cancer-related genes may be affected by MTHFR polymorphisms.

Chemopreventive Agents and Inhibitors of Cancer Hallmarks: May Citrus Offer New Perspectives?

Fruits and vegetables have long been recognized as potentially important in the prevention of cancer risk. Thus, scientific interest in nutrition and cancer has grown over time, as shown by increasing number of experimental studies about the relationship between diet and cancer development. This review attempts to provide an insight into the anti-cancer effects of Citrus fruits, with a focus on their bioactive compounds, elucidating the main cellular and molecular mechanisms through which they may protect against cancer. Scientific literature was selected for this review with the aim of collecting the relevant experimental evidence for the anti-cancer effects of Citrus fruits and their flavonoids. The findings discussed in this review strongly support their potential as anti-cancer agents, and may represent a scientific basis to develop nutraceuticals, food supplements, or complementary and alternative drugs in a context of a multi-target pharmacological strategy in the oncology.

Natural iron chelators: Protective role in A549 cells of flavonoids-rich extracts of Citrus juices in Fe(3+)-induced oxidative stress

Exogenous iron in particulate matter and imbalanced iron homeostasis cause deleterious effects on health. Natural and synthetic iron chelators may be of therapeutic benefit, therefore we evaluated the protective effect of Citrus flavonoids-rich extracts from bergamot and orange juices in iron overloaded human lung epithelial cells. Cytofluorimetric, biochemical and genotoxic analyses were performed in Fe2(SO4)3 exposed A549, pretreated with each extract whose chemical composition was previously detected. Chelating activity was assessed in cells by a calcein ester. Both extracts reduced the generation of reactive oxygen species and membrane lipid peroxidation, improved mitochondrial functionality, and prevented DNA-oxidative damage in iron-exposed cells. Antioxidant effects were attributed to the chelating property, blocking upstream the redox activity of iron. Flavonoid-rich extracts also induced antioxidant catalase. The bergamot and orange juice extracts had a broad-spectrum protective effect. Their use prevents iron oxidative injury and these natural iron chelators could be used as therapeutic agents.

Citrus bergamia Juice Extract Attenuates β-Amyloid-Induced Pro-Inflammatory Activation of THP-1 Cells Through MAPK and AP-1 Pathways

Flavonoids have been shown to be effective in protecting against age-related cognitive and motor decline in both in vitro and in vivo models. Recently, a flavonoid-rich extract of Citrus bergamia juice (BJe) has been shown to display anti-oxidant and anti-inflammatory properties against LPS-induced activation of human THP-1 monocytes. In the light of these observations, we wondered whether BJe may be beneficial against neuroinflammatory processes, such as those observed in Alzheimer’s disease. To this aim we used THP-1 monocytes to investigate the mechanisms underlying the beneficial potential of BJe against amyloid-beta_1–42 (Aβ₁₋₄₂) -mediated inflammation. Exposure of THP-1 cells to Aβ₁₋₄₂ significantly induced the expression and secretion of IL-6 and IL-1β in THP-1 cells and increased the phosphorylation of ERK 1/2 as well as p46 and p54 members of JNK family. Moreover, Aβ₁₋₄₂ raises AP-1 DNA binding activity in THP-1-treated cells. Interestingly, all these effects were reduced in the presence of BJe. Our data indicate that BJe may effectively counteract the pro-inflammatory activation of monocytes/microglial cells exposed to amyloid fibrils, suggesting a promising role as a natural drug against neuroinflammatory processes.

In vitro effect of bergamot (Citrus bergamia) juice against cagA-positive and-negative clinical isolates of Helicobacter pylori

Background

Helicobacter pylori infection has been associated with chronic gastritis, peptic ulcer and gastric carcinoma as over half of the world's population is colonized with this gram-negative bacterium. Due to the increasing antibiotic resistance, its eradication rates fails in a great portion of patients. A number of studies showed that molecules largely distributed in commonly consumed fruits and vegetables may have antimicrobial activity. The aim of the present study was to investigate the effect of bergamot juice (BJ) against Helicobacter pylori in vitro. The potential therapeutic combination between BJ and the antibiotics amoxicillin (AMX), clarithromycin (CLA) and metronidazole (MTZ) has also been evaluated.

Methods

The minimum inhibitory concentration (MIC) of BJ, AMX, CLA and MTZ against 2 ATCC and 32 clinical isolates of H. pylori was assayed according to CLSI. The checkerboard method was used to determine the efficacy of the association BJ with the three reference antibiotics.

Killing curves were performed on the two cagA-positive ATCC strains of H. pylori (ATCC 43504 and ATCC 49503), on the clinical isolate cagA-positive HP6 strain of H. pylori and on the clinical isolate cagA-negative HP61 strain of H. pylori.

Results

BJ (2.5 %, v/v) inhibited the growth of 50 % of the H. pylori clinical isolates, whereas 5 % (v/v) inhibited 90 %. AMX was the most effective antibiotic against the reference strains and the clinical isolates, followed by CLA and MTZ. In the combination assays, synergism was observed between BJ and AMX and between BJ and MTZ against both the reference strains and the clinical isolates. Indifference was observed between BJ and CLA.

Conclusions

BJ was effective in vitro against H. pylori and the genotype status of the clinical strains may have an impact on its susceptibility. The synergistic combination of BJ and antibiotics could be used to prevent or treat resistance.

Effects of bergamot essential oil and its extractive fractions on SH-SY5Y human neuroblastoma cell growth

Objectives

The goals were to investigate the mechanisms underlying the antiproliferative effects of bergamot essential oil (BEO) and to identify the compounds mainly responsible for its SH-SY5Y cells growth rate inhibition.

Methods

Five BEO extractive fractions (BEOs) differing in their chemical composition were used. Cell proliferation was determined by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and cell count assays. Trypan blue exclusion test and Annexin V/PI staining were performed to assess their cytotoxic activity. Genotoxicity was detected by comet assay. The cell cycle was checked cytofluorimetrically. Reactive oxygen species (ROS) and Δψm were measured fluorimetrically. Western blotting analyses for some apoptosis-related proteins were carried out.

Key findings

Treatment of SH-SY5Y cells with some types of BEOs decreased cell growth rate by a mechanism correlated to both apoptotic and necrotic cell death. Coloured BEOs act by increasing ROS generation, responsible for the drop in Δψm, and modulate p38 and extracellular signal-regulated kinases (ERK ½) mitogen-activated protein kinases, p53, Bcl-2 and Bax signalling pathways. Finally, we identify bergamottin and 5-geranyloxy-7-methoxycoumarin as the bioactive molecules that could play a pivotal role in the antiproliferative effects exerted by coloured BEOs.

Conclusions

Our study provides novel insights into the field of the antiproliferative effects of BEO, which could be exploited in the context of a multitarget pharmacological strategy.

Transglutaminase 2 is involved in homocysteine-induced activation of human THP-1 monocytes

Aberrant transglutaminase 2 (TG2) expression and protein cross-linking activity have been associated with several chronic neurodegenerative disorders in which inflammatory processes triggered by activated microglia and monocytes play a key role, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. Interestingly, mild-to-moderate hyperhomocysteinemia (HHcy), corresponding to increased plasma homocysteine (Hcy) concentrations in the range 16-60 μM, have recently been associated with the above-cited diseases. Using THP-1 monocytes, here we investigated the role of TG2 in cell response to mildly elevated Hcy concentrations. A five-day incubation with Hcy (∼25 μM) increased reactive oxygen species, peroxide lipids, as well as 8-hydroxyguanosine levels by twofold, and decreased the endogenous cell antioxidant defenses, that is reduced glutathione, by 50% in Hcy-exposed cultures compared with controls (p < 0.01). Hcy-induced oxidative stress was associated with increases in TG2 expression and activity, as well as nuclear factor kappa B activation. Notably, the latter was reduced in the presence of the TG-specific inhibitor R283. Hcy exposure also significantly increased the mRNA levels of tumor necrosis factor alpha, interleukin (IL)-6, and IL-1β, as well as the level of Hcy-inducible endoplasmic reticulum (ER) stress protein, a marker of ER stress, in Hcy-exposed cultures compared with controls. Notably, these effects were dramatically reduced by R283. These preliminary findings indicate that TG2 plays a key role in Hcy-induced activation of THP-1 monocytes, involving oxidative as well as ER stress and inflammation. This underlines the potential of TG2 inhibition in the therapeutic management of inflammatory processes contributing to neurodegenerative disorders associated with mild HHcy.

Flavonoid fraction of Bergamot juice reduces LPS-induced inflammatory response through SIRT1-mediated NF-κB inhibition in THP-1 monocytes

Plant polyphenols exert anti-inflammatory activity through both anti-oxidant effects and modulation of pivotal pro-inflammatory genes. Recently, Citrus bergamia has been studied as a natural source of bioactive molecules with antioxidant activity, but few studies have focused on molecular mechanisms underlying their potential beneficial effects. Several findings have suggested that polyphenols could influence cellular function by acting as activators of SIRT1, a nuclear histone deacetylase, involved in the inhibition of NF-κB signaling. On the basis of these observations we studied the anti-inflammatory effects produced by the flavonoid fraction of the bergamot juice (BJe) in a model of LPS-stimulated THP-1 cell line, focusing on SIRT1-mediated NF-κB inhibition. We demonstrated that BJe inhibited both gene expression and secretion of LPS-induced pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) by a mechanism involving the inhibition of NF-κB activation. In addition, we showed that BJe treatment reversed the LPS-enhanced acetylation of p65 in THP-1 cells. Interestingly, increasing concentrations of Sirtinol were able to suppress the inhibitory effect of BJe via p65 acetylation, underscoring that NF-κB-mediated inflammatory cytokine production may be directly linked to SIRT1 activity. These results suggest that BJe may be useful for the development of alternative pharmacological strategies aimed at reducing the inflammatory process.

Effect of Citrus bergamia juice on human neuroblastoma cells in vitro and in metastatic xenograft models

Neuroblastoma is the most common extracranial pediatric solid tumor with poor prognosis in children with disseminated stage of disease. A number of studies show that molecules largely distributed in commonly consumed fruits and vegetables may have anti-tumor activity. In this study we evaluate the effect of Citrus bergamia (bergamot) juice (BJ) in vitro and in a spontaneous metastatic neuroblastoma SCID mouse model. Qualitative and quantitative characterizations of BJ flavonoid fractions were performed by RP-HPLC/PDA/MS. We show that BJ significantly affects SK-N-SH and LAN-1 cell proliferation in vitro, but fails to reduce primary tumor weight in vivo. Moreover, BJ reduced cell adhesiveness and invasion of LAN-1 and SK-N-SH cells in vitro and the number of pulmonary metastases under consideration of the number of tumor cells in the blood in mice inoculated with LAN-1 cells in vivo. These effects without any apparent sign of systemic toxicity confirm the potential clinical interest of BJ and lay the basis for further investigation in cancer.

Protective effects of zonisamide against rotenone-induced neurotoxicity

Zonisamide (ZNS), an antiepileptic drug having beneficial effects also against Parkinson's disease symptoms, has proven to display an antioxidant effects in different experimental models. In the present study, the effects of ZNS on rotenone-induced cell injury were investigated in human neuroblastoma SH-SY5Y cells differentiated towards a neuronal phenotype. Cell cultures were exposed for 24 h to 500 nM rotenone with or without pre-treatment with 10-100 μM ZNS. Then, the following parameters were analyzed: (a) cell viability; (b) intracellular reactive oxygen species production; (c) mitochondrial transmembrane potential; (d) cell necrosis and apoptosis; (e) caspase-3 activity. ZNS dose-dependently suppressed rotenone-induced cell damage through a decrease in intracellular ROS production, and restoring mitochondrial membrane potential. Similarly to ZNS effects, the treatment with N-acetyl-cysteine (100 μM) displayed significant protective effects against rotenone-induced ROS production and Δψm at 4 and 12 h respectively, reaching the maximal extent at 24 h. Additionally, ZNS displayed antiapoptotic effects, as demonstrated by flow cytometric analysis of annexin V/propidium iodide double staining, and significant attenuated rotenone-increased caspase 3 activity. On the whole, these findings suggest that ZNS preserves mitochondrial functions and counteracts apoptotic signalling mechanisms mainly by an antioxidant action. Thus, ZNS might have beneficial effect against neuronal cell degeneration in different experimental models involving mitochondrial dysfunction.

Effects of low intensity static magnetic field on FTIR spectra and ROS production in SH-SY5Y neuronal-like cells

Biological effects of man-made electromagnetic fields (EMFs) have been studied so far by experimental approaches exposing animals and cell cultures to EMFs. However, the evidence for cell toxicity induced by static magnetic field (SMF) is still uncertain. We investigated the effects produced by the exposure of human SH-SY5Y neuronal-like cells to a uniform magnetic field at intensities of 2.2 mT, which is less than the recommended public exposure limits set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). A decrease of membrane mitochondrial potential up to 30% was measured after 24 h of exposure to SMF in SH-SY5Y cells, and this effect was associated with reactive oxygen species production increase. Fourier transform infrared spectroscopy (FTIR) analysis showed that exposure to a static magnetic intensity around 2.2 mT changed the secondary structure of cellular proteins and lipid components. The vibration bands relative to the methylene group increased significantly after 4 h of exposure, whereas further exposure up to 24 h produced evident shifts of amide I and II modes and a relative increase in β-sheet contents with respect to α-helix components. Our study demonstrated that a moderate SMF causes alteration in cell homeostasis, as indicated by FTIR spectroscopy observations of changes in protein structures that are part of cell response to magnetic field exposure.

Transglutaminase 2 and phospholipase A₂ interactions in the inflammatory response in human Thp-1 monocytes

Several experimental approaches have demonstrated that transglutaminase 2 (TG2) increased activity is involved in monocyte activation and inflammatory response. Preliminary results also demonstrate a TG-mediated post-translational modification of phospholipase A2 (PLA2), which catalyzes the release of arachidonic acid from its lipid storage sites. The control of PLA2-mediated production of eicosanoids has been found to be of great benefit for inflammatory disease treatment. However, the identification of the mechanisms of PLA2 activation is a very complex issue, because of the presence of multiple PLA2 forms. The aim of this study was to characterize the interactions between TG2 and sPLA2 in LPS-stimulated THP-1 cells, which were treated with TPA to induce early differentiated macrophage-type model. We demonstrated that increases in TG2 enzyme activity and protein expression may be considered an early event in monocyte/macrophage activation by LPS. Under these conditions, TG2 protein was co-immunoprecipitated with PLA2 by monoclonal antibody directed against the secretory form of the enzyme (sPLA2-V). Concomitantly, the PLA2 enzyme activity increased in TPA-treated cells exposed to LPS; these high levels of enzyme activity were significant reduced by R283, a site-specific inhibitor of TG2. Moreover, confocal laser scanning microscopy analysis of double-immunostained cytochemical specimens confirmed a co-localization of BAPA-labeled proteins and sPLA2-V in LPS-treated cells. These findings give evidence of a complex TG2/sPLA2-V, suggesting the possibility that sPLA2-V is a substrate for TG2. These results demonstrated that TG2 increases produced a sustained activation of PLA2 activity, suggesting a functional interaction between these enzymes in the regulation of inflammatory response.

Mechanisms underlying the anti-tumoral effects of Citrus Bergamia juice

Based on the growing deal of data concerning the biological activity of flavonoid-rich natural products, the aim of the present study was to explore in vitro the potential anti-tumoral activity of Citrus Bergamia (bergamot) juice (BJ), determining its molecular interaction with cancer cells. Here we show that BJ reduced growth rate of different cancer cell lines, with the maximal growth inhibition observed in neuroblastoma cells (SH-SY5Y) after 72 hs of exposure to 5% BJ. The SH-SY5Y antiproliferative effect elicited by BJ was not due to a cytotoxic action and it did not induce apoptosis. Instead, BJ stimulated the arrest in the G1 phase of cell cycle and determined a modification in cellular morphology, causing a marked increase of detached cells. The inhibition of adhesive capacity on different physiologic substrates and on endothelial cells monolayer were correlated with an impairment of actin filaments, a reduction in the expression of the active form of focal adhesion kinase (FAK) that in turn caused inhibition of cell migration. In parallel, BJ seemed to hinder the association between the neural cell adhesion molecule (NCAM) and FAK. Our data suggest a mechanisms through which BJ can inhibit important molecular pathways related to cancer-associated aggressive phenotype and offer new suggestions for further studies on the role of BJ in cancer treatment.

Influence of Polymorphism −308 G/A of the Tnf-α Gene on High Mobility Group Box-1 Protein in Rheumatoid and Spondylo-Arthritis Patients

Single nucleotide polymorphism (SNP) in the human Tumor Necrosis Factor-α(TNF-α) gene promoter, the −308 G/A variant, has been associated with increased TNF-α levels that may amplify the severity of rheumatoid arthritis (RA) and a poor responsiveness to TNF-α blockade therapy. High mobility group box protein (HMGB-1) is a pro-inflammatory cytokine that plays a pivotal role in the pathogenesis of RA and may be an original target of therapy. The aim of this study is to investigate whether the −308 G/A variant of the TNF-α gene is associated with altered expression of HMBG-1. A total of 110 consecutive patients with rheumatoid arthritis and spondylo-arthritis (ankylosing spondylitis, psoriatic arthritis and spondylitis associated with inflammatory bowel disease) referring to the Rheumatology Unit of Messina University Hospital were enrolled. Patients were genotyped for the −308 TNF-α gene promoter polymorphism. Clinical status was also assessed. HMGB-1 and TNF-α mRNA(Real Time PCR) from total blood and plasmatic HMGB-1 (Western Blot analysis) and TNF-α (ELISA) protein were also evaluated. Irrespective of the underlying disease, patients carrying the G/A genotype showed enhanced HMGB-1 and TNF-α mRNA levels and increased circulating concentration of the inflammatory cytokines when compared to patients with G/G genotype. The data suggest that subjects carrying the TNF-α −308G/A genotype have enhanced expression of HMGB-1 protein that may explain, at least in part, the increased severity of the disease.

Modulation of heat shock protein response in SH-SY5Y by mobile phone microwaves

AIM

To investigate putative biological damage caused by GSM mobile phone frequencies by assessing electromagnetic fields during mobile phone working.

METHODS

Neuron-like cells, obtained by retinoic-acid-induced differentiation of human neuroblastoma SH-SY5Y cells, were exposed for 2 h and 4 h to microwaves at 1800 MHz frequency bands.

RESULTS

Cell stress response was evaluated by MTT assay as well as changes in the heat shock protein expression (Hsp20, Hsp27 and Hsp70) and caspase-3 activity levels, as biomarkers of apoptotic pathway. Under our experimental conditions, neither cell viability nor Hsp27 expression nor caspase-3 activity was significantly changed. Interestingly, a significant decrease in Hsp20 expression was observed at both times of exposure, whereas Hsp70 levels were significantly increased only after 4 h exposure.

CONCLUSION

The modulation of the expression of Hsps in neuronal cells can be an early response to radiofrequency microwaves.

The ESR2 AluI gene polymorphism is associated with bone mineral density in postmenopausal women

Multiple factors may contribute to the pathogenesis of postmenopausal osteoporosis including environmental, life-style and genetic factors. Common variants in ESR2 gene encoding for ER-beta, highly expressed in bone tissue, have recently been proposed as candidates for affecting bone phenotype at the population level, particularly in postmenopausal women. In this study, we examined the genetic background at ESR2 AluI (rs4986938, 1730G>A) locus in 89 osteopenic, postmenopausal women (age range 49-56 years) together with BMD at lumbar spine and femoral neck sites as well as variations in plasma levels of bone metabolism and turnover markers. Genotyping for ESR2 G1730A polymorphism showed that the frequency of A mutated allele accounted for 0.4 in our cohort of postmenopausal women; moreover, the GA1730 heterozygous individuals were the most represented (50.6%) compared with GG (37.8%) and AA homozygous ones (14.6%). A regression analysis showed that lumbar spine BMD values were significantly associated with both ESR2 AA1730 genotype (p=0.044) and time since the onset of menopause (p=0.031), while no significant association was detected between biochemical markers and genetic background. Interestingly, 85% of patients with AA1730 genotype presented the smallest lumbar spine BMD values. These findings first indicate a worsening effect of ESR2 AluI polymorphism on lumbar spine BMD reduction in postmenopause, suggesting that the detection of this ESR2 variant should be recommended in postmenopausal women, particularly in populations with a high prevalence of ESR2 AA1730 homozygous genotype.

Agmatine effects on mitochondrial membrane potential and NF-κB activation protect against rotenone-induced cell damage in human neuronal-like SH-SY5Y cells

Agmatine, an endogenous arginine metabolite, has been proposed as a novel neuromodulator that plays protective roles in the CNS in several models of cellular damage. However, the mechanisms involved in these protective effects in neurodegenerative diseases are poorly understood. The present study was undertaken to investigate the effects of agmatine on cell injury induced by rotenone, commonly used in establishing in vivo and in vitro models of Parkinson's disease, in human-derived dopaminergic neuroblastoma cell line (SH-SY5Y). We report that agmatine dose-dependently suppressed rotenone-induced cellular injury through a reduction of oxidative stress. Similar effects were obtained by spermine, suggesting a scavenging effect for these compounds. However, unlike spermine, agmatine also prevented rotenone-induced nuclear factor-κB nuclear translocation and mitochondrial membrane potential dissipation. Furthermore, rotenone-induced increase in apoptotic markers, such as caspase 3 activity, Bax expression and cytochrome c release, was significantly attenuated with agmatine treatment. These findings demonstrate mitochondrial preservation with agmatine in a rotenone model of apoptotic cell death, and that the neuroprotective action of agmatine appears because of suppressing apoptotic signalling mechanisms. Thus, agmatine may have therapeutic potential in the treatment of Parkinson's disease by protecting dopaminergic neurons.

Intracellular accumulation of cell cycle regulatory proteins and nucleolin re-localization are associated with pre-lethal ultrastructural lesions in circulating T lymphocytes: the HIV-induced cell cycle dysregulation revisited

The HIV-induced demise of CD4-T cells is thought to be a result of the execution of genetically programmed cell death that occurs in lymphoid tissue, where many resident T cells are chronically hyperactivated. Since HIV-induced alterations of cell cycle control has been often indicated as prominent mechanism of immune hyper activation and cause of apoptotic death, the signal pathway involved in cell cycle dysregulation of T lymphocytes from HIV infected patients was extensively studied. Here, we also demonstrate that circulating T lymphocytes leave lymphoid tissues with diffused regressive lesions (vacuolization, blebbing, nuclear evanescence and organelle swelling). Equally diffused are biochemical anomalies that accompany the overall disarrangement of cell structure, particularly the fragmentation and diffusion into the cytoplasm of C23/nucleolin, the intracellular accumulation of short lived regulatory proteins and the decrease in expression of membrane proteins. All this is something more than a cell cycle-related remodelling of cell morphology and biochemical mechanisms, and rather recalls a necrotic/oncotic cell damage. Since these changes are associated with adaptive mechanisms to hypoxia, we give evidence for alteration of cell cycle control developing in conditions of scarce energy supply.

Homocysteine, vitamin determinants and neurological diseases

This review focuses on the putative role of hyper-homocysteinemia in the pathogenesis of different diseases affecting the nervous system, including stroke, Alzheimer's disease, Parkinson's disease, epilepsy, multiple sclerosis and amyotrophic lateral sclerosis. However, a firm pathogenic role of homocysteine in these diseases has never been established. Lowering plasma homocysteine levels trough vitamin therapy failed to prevent vascular diseases. Conversely, normalization of hyper-homocysteinemia caused improvement in patients with cognitive impairment. B vitamin deficiency is the main determinant of homocysteine levels. However, it has been hypothesized that homocysteine might be a mere marker of vitamin deficiency or an indicator of disease rather than a risk factor. A more consistent use of thresholds to define deficiency is needed to recommend routine screening, monitoring and supplementation of B vitamins to ameliorate the prognosis of the above mentioned disorders. To date, data are insufficient to firmly establish which one of the hypotheses made is correct and the question concerning the real meaning of hyper-homocysteinemia in the pathology of the nervous system still remains an intriguing medical dilemma.

Critical role of transglutaminase and other stress proteins during neurodegenerative processes

Proteolytic stress, resulting from the intracellular accumulation of misfolded or aggregated proteins, which exceed the capacity of the ubiquitin-proteasome system to degrade them, plays a relevant role in neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and Huntington's chorea. Most of toxic protein aggregates are characterised by the presence of isopeptide bonds (cross-links) catalysed by transglutaminase activity; further, several disease-specific proteins-tau, amyloid-beta, alpha-synuclein, huntingtin-are in vitro and/or in vivo substrates of transglutaminase 2. These findings suggest an important role for transglutaminase 2-mediated cross-linking reactions in neurodegeneration. Therefore, the use of transglutaminase activity inhibitors could ameliorate neuronal cell death. New therapeutic perspectives also arise from the possibility to prevent or reduce protein aggregation by enhancing the activation of heat shock proteins, which have been shown to be potent suppressors of neurodegeneration in cell cultures/animal models. Interestingly, some heat shock proteins have been shown to be in vitro or in vivo cross-linked by transglutaminase 2. These observations seem to suggest that transglutaminase activity could be involved in the stabilization of intracellular protein aggregates by interfering with proteasomal degradation of misfolded proteins. Further studies are needed to validate leading hypotheses and to open new prospects for developing therapeutic tools.

NF-kappaB activation is associated with homocysteine-induced injury in Neuro2a cells

Background

Perinatal exposure to hyperhomocysteinemia might disturb neurogenesis during brain development and growth. Also, high levels of homocysteine trigger neurodegeneration in several experimental models. However, the putative mechanisms of homocysteine-induced toxicity in the developing nervous system have poorly been elucidated. This study was aimed to investigate homocysteine effects in undifferentiated neuroblastoma cells, Neuro2a.

Results

A 4 h exposure to homocysteine in a concentration range of 10–100 μM did not affect cell viability and ROS production in Neuro2a cell cultures. Instead, ROS levels were increased by two-three folds in cells treated with 250 μM and 500 μM homocysteine, respectively, in comparison with control cells. Also, the highest homocysteine dose significantly reduced the viable cell number by 40%. Notably, the treatment with homocysteine (250 μM–500 μM) in the presence of antioxidants, such as N-acetylcysteine and IRFI 016, a synthetic α-tocopherol analogue, recovered cell viability and significantly reduced homocysteine-evoked increases in ROS production. Moreover, antioxidants, particularly IRFI 016, were able to counteract NF-κB activation induced by 250 μM homocysteine.

Cell treatment with 250 μM homocysteine also triggered the onset of apoptosis, as demonstrated by the increased expression of early apoptotic markers such as Bax, caspase-3 and p53. In contrast, Bcl2 expression was not affected by homocysteine exposure. Interestingly, the specific inhibition of NF-κB nuclear translocation by the synthetic peptide SN50 was able to almost completely suppress the homocysteine-evoked rises in pro-apoptotic protein expression as well as in caspase-3 activity. Further, also IRFI 016 and N-acetylcysteine were able to significantly reduce caspase-3 activation induced by homocysteine treatment.

Conclusion

These observations suggest an involvement of redox state alterations and activated NF-κB in apoptosis onset triggered by homocysteine in neuroblastoma cells Neuro2a. However, further investigations are needed to characterize molecular events involved in the NF-κB activation induced by homocysteine.

Transglutaminase 2 and NF-kappaB interplay during NGF-induced differentiation of neuroblastoma cells

NGF treatment of neuroblastoma cells stimulates outgrowth of neurite processes associated with the expression of TrkA receptor and several differentiation markers. In this study, a 6 DIV exposure to NGF (50 ng/ml) increased immunostaining for alpha-tubulin, and expression of both alpha-tubulin and protein kinase C in the neuroblastoma cell line Neuro2a. Further, up-regulation of transglutaminase 1 and transglutaminase 2 expression, and reduction of transglutaminase 3 levels, were also observed in NGF-treated cells in comparison to untreated cells. Moreover, when Neuro2a cells were treated with the specific NF-kappaB inhibitor SN-50, the strong reduction of NF-kappaB activation was concomitant with a significant decrease of transglutaminase 2 expression, suggesting that NGF-evoked transglutaminase 2 induction could be related to NF-kappaB activation. To characterize the possible transglutaminase 2/NF-kappaB interplay, NGF treatment was carried out in Neuro2a cells which already over-expressed transglutaminase 2 after retinoic acid treatment. An additive effect of NGF was observed on the retinoic acid-induced transglutaminase 2 expression and enzyme activity, and NF-kappaB activation. However, a cystamine-mediated significant inhibition of transglutaminase activity (70%) was accompanied by a drastically reduced NF-kappaB activation only in cells exposed to NGF following retinoic acid treatment. We hypothesize that NF-kappaB activation was dependent on the transamidating activity related to high levels of TG2, and NGF enhanced NF-kappaB activation by a different, synergistically acting, pathway. These data suggest that the combined use of NGF and retinoic acid, or mimicking drugs, may provide the basics for the development of novel strategies in the therapeutic management of neuroblastomas.

Homocysteine induces DNA damage and alterations in proliferative capacity of T-lymphocytes: a model for immunosenescence?

Homocysteine (Hcy) appears to exert different effects on immune functions possibly contributing to age-related pathological states, including vascular diseases, immune dysfunction, and Alzheimer's disease. However, molecular mechanisms underlying Hcy toxicity need to be better characterized. Since T cells are a suitable model to address the possible role of replicative senescence during the in vivo aging, we investigated the effects of high Hcy concentrations on mitogen-activated lymphocytes, with regard to evaluation of DNA damage and cell cycle alterations. Cultured human peripheral blood lymphocytes were stimulated with mitogenic concanavalin A (5 microg/ml) for 48 h in the presence or absence of Hcy (1 mM). Both flow cytometric analysis and caspase-3 activity assay showed an increased rate of apoptosis in Hcy-treated lymphocyte cultures compared to controls. Further, Hcy exposure caused DNA fragmentation as evaluated by single cell gel electrophoresis showing the occurrence of comets. Cytokinesis-block micronucleus assay, performed after addition of cytochalasin B (5 microg/ml) and incubation up to 72 h, revealed a significantly higher frequency of micronucleated/binucleated cells in Hcy-treated cultures compared to controls (P < 0.001). Hcy also reduced cyclin B expression in comparison to control cultures, while cyclin D levels were not significantly affected. Cell cycle alterations, such as the inability of cells to enter into mitosis, could be related with DNA damage. These findings provided a link between perturbation of lymphocyte proliferation homeostasis and commitment towards apoptosis. Our results suggest the involvement of Hcy in the altered immune function associated with age and disease pathology.

Prevalence of SENV-H and SENV-D virus: epidemiological study in blood donors and dialysis patients

INTRODUCTION

Recently, the identification of the SEN virus as a possible etiological agent of parental transmission hepatitis led to the study of the prevalence of such pathogen agents, particularly SENV-H, in our population. This paper compares the rate prevalence in high-risk subjects, such as dialysis patients, and low-risk subjects, such as blood donors.

MATERIAL AND METHODS

The study was carried out on SEN virus DNA extracted from serum of dialysis patients and blood donors, and the presence of viral genomes was performed by the nested PCR method.

RESULTS

The results showed a higher prevalence in male blood donors, supporting the hypothesis of an epidemiological role for sexual and also parental transmission, as is clearly demonstrated by the high prevalence in dialysis patients. The result reduced the importance of the possible etiological role of the SEN virus due to the high percentage of positivity in healthy population, and it induces one to consider poorly significant the pathogenicity of such viral agents.

CONCLUSION

For this instance, the authors, in agreement with the phylogenically related TT virus, described SEN viruses as absolutely not pathogens and considered them as "simple guests."